Portable utility system

ABSTRACT

A portable utility system particularly useful for drastically cooling seawater and/or forming an ice/brine slurry for application to fish. A tube-in-tube evaporator is provided for cooling the seawater while it is drawn into the evaporator by means of a positive displacement brine pump. Seawater is drawn into a tube-in-tube condenser by a coolant pump to remove heat from the system refrigerant and is continuously discharged after it is passed through the condenser coils. A compressor is provided to raise the pressure and temperature of the gaseous refrigerant. A reversible valve enables the flow of refrigerant through the system to be reversed, producing hot water at the output of the evaporator, when desired. The evaporator is formed of a first tube for conveying refrigerant and a second tube positioned in heat exchange relation within the first tube, the second tube conveying seawater to be refrigerated. The condenser may also be formed of a tube within a tube wherein the refrigerant is conveyed in the inner tube and the cooling seawater is conveyed in the outer tube. An in-line dispenser for bacteriostatic agents, or the like, can be provided. The system can supply electrical as well as hydraulic needs and can be used onshore with air cooling in place of water cooling.

United States Patent [191 Lowi, Jr.

'61] 3,822,566 [451 July 9,1974

[ PORTABLE UTILITY SYSTEM [76] Inventor: I

San Pedro, Calif. 90732 [22] Filed: July 13, 1972 [21] Appl. No.:271,457

[52] US. or. ..62/435,62/325,62/324, 62/240, 62/64, 62/78, 62/98, 62/99,62/439 51 Int. Cl F25d 17/02 [58] Field of Search 62/324, 240, 435, 98,99, 62/64, 185, 201, 325

[56] References Cited UNITED STATES PATENTS 1,712,568 5/1929 Kritzer62/185 2,136,813 11/1938 Dobson 62/98 2,299,188 10/1942 Stork 62/992,511,582 6/1950 Grindrod 62/98 2,513,373 7/1950 Sporn 62/324 2,596,1955/1952 Arbuckle 62/435 2,620,635 12/1952 lnautner 62/185 2,746,2725/1956 Carpenter 62/240 2,966,779 1/1961 Lintern 62/240 3,540,229 1H1970 Bunten 62/240 SOCT/ON PUMP Alvin Lowi, Jr., 2146 Toscanini Dr,

[57 ABSTRACT A portable utility system particularly useful fordrastically cooling seawater and/or forming an ice/brine slurry forapplication to fish. A tube-in-tube evaporator is provided for coolingthe seawater while it is drawn into the evaporator by means of apositive displacement brine pump. Seawater is drawn into a tubein-tubecondenser by a coolant pump to remove heat from the system refrigerantand is continuously discharged after it is passed through the condensercoils. A compressor is provided to raise the pressure and temperature ofthe gaseous refrigerant. A reversible valve enables the flow ofrefrigerant through the system to be reversed, producing hot water atthe output of the evaporator, when desired. The evaporator is formed ofa first tube for conveying refrigerant and a second tube positioned inheat exchange relation within the first tube, the second tube conveyingseawater to be refrigerated. The condenser may also be formed of a tubewithin a tube wherein the refrigerant is conveyed in the inner tube andthe cooling seawater is conveyed in the outer tube. An in-1ine dispenserfor bacteriostatic agents, or the like, can be provided. The system cansupply electrical as well as hydraulic needs and can be used onshorewith air cooling in place of water cooling. 1

4 Claims, 2 Drawing Figures 1 PORTABLE UTILITY SYSTEM FIELD OF THEINVENTION BACKGROUND AND SUMMARY OF THE INVENTION The principal sourcesof commercial marketable sea food in the world today are remote in timeand distance from their ultimate consumers. Unlike meat products, suchas beef, which are actually improved with aging, seafood is highlyperishable. Fish begin to deteriorate as soon as caught and immediaterefrigeration is the only known way to preserve the original quality ofthe fish. Much of the worlds high quality seafood is taken in warmtropical waters by small craft which typically have no refrigerationsystem at all or, at best, utilize ice. Therefore, a significantpercentage of the fish catch spoils before it can reach processingfacilities. It is not uncommon for such spoilage to amount to more thanhalf the value of the catch. Thus preservation and quality control arethe fundamental obstacles confronting the advancement ofcommercialfishing in much of the world today. 1

The changing technology of fishing actually favor the use of small boatsin many areas where new commercial fisheries are being developed.Moreover,there is a growing tendency for largeseafood companies toestablish canning and processing plants in underdeveloped areas ofthe'world and to buy fish from native fisherman.

Typical fishing boats without refrigeration can keep their catch on theboat for up to a maximum of 24 hours. Thus, fish caught early in thetrip may spoil be fore a full load has been caught. Custom refrigerationsystems for such fishing boats have been relatively expensive, oftencosting more than the market value of the'boat itself. The use of thecustomrefrigeration systerns has been limited to shrimp boats of greaterthan .60 feet in length and this guideline has only been foundacceptable in recent years, as the price of shrimp has greatlyincreased. Thus, inexpensive refrigeration systemscould substantiallyboost the yield for a fishing boat by increasing the amount ofmarketable fish and, by preserving quality, assuring a higher price perpound of fish at the time of sale.

Prior art'devices which utilize chilled seawater are relatively complexand expensive. In addition, these refrigeration systems are not readilyrepaired by a fishing crew while the boat is at sea. Typical systemswhich involved the spraying of fish for refrigeration purposes includeUS. Pat. Nos. 2,746,272, 2,982,109 and, 3,162,020. Also of interest withrespect to the cooling and heating functions of a refrigeration systemare US. Pat. Nos. 2,887,853, 3,308,877 and 3,453,840. Additional patentswhich are of background and environmental interest include US. Pat. Nos.1,322,312, 1,192,896, 2,863,037, 2,909,040 and 3,309,891.

In order to overcome the disadvantages of priorart refrigerationsystems, the present invention provides an economical, portable sourceof refrigeration suitable for use in commercial fishing operations bysmall craft. a

In addition, the refrigeration system can also be used on large boatsandshore facilities and requires only seawater and ordinary motor fuelfor its operation. Refrigeration occurs by the direct contact of theseafood with a stream of refrigerated seawater or an ice/brine slurry.An advantage of the system is that immediate chilling of the fishoccurs, which is superior to ice or other conventional refrigerationmethods. When utilized with fish caught from warm ocean water, therefrigerated seawater is lowered to about 31-39F, thereby reducingspoilage from enzymatic attack and suppressing the activity ofmesophillic bacteria of these waters which are substantially dormant attemperatures below 50F. In addition, cold water fish may spoil frompsychrophillic bacterial attack at temperatures as low as 19F Thus, forapplication with cold water fishing vessels the system is designed toproduce ice/brine slurrys, without additional salt requirement, fromrecycled refrigerated seawater at temperatures as low as 15F. The systemthus has the capability of freezing aswell as chillingthe fish. a

The refrigeration system is designed to produce an ice/ brine slurry bytaking advantage of the fact that seawater has no definite freezingpoint. Due to its dissolved minerals, the seawater does not solidify atonce, but forms ice (fresh water) crystals suspended in the residualbrine as its temperature is reduced, the first crystals being formed atabout 29F. With further reduction of temperature, more and more crystalsform, taking water out of the solution and leaving a brine of higher andhigher salt content as the matrix. The slurry of ice crystals and brinebecomes more and more vis- 4 The pump is of a positive displacementconfiguration so that ice crystals are pushed through a tube byincreasing pressure as the ice/brine slurry becomes more viscous. Theevaporator of the systemis formed of a first tube for conveying arefrigerant and a second tube member positionedwithin the first tubemember through which the seawater is pumped. In addition, a pump isprovided forcontinuouslly dischargingwater through a condenser so as, toremove heat from the compressed refrigerant. The condenser is alsoconstructed tube-in-tube. Cooling seawater passes-through the innertube, Heat is removed from the condenser by seawater in the outer tube.

In a further embodiment, a reversible valve is provided for reversingthe flow of refrigerant through the system, thereby producing hot waterat the output of the evaporator.

As a result of providing the novel portable refrigeration capability, asoutlined above, small boats will be able to remain in the fishery formuch longer periods of time. As a consequence, greater need will existfor supportive utilities suchas electrical power, hot cleaning water,drinking water, bilge pumping and other water transport capability. Thesystem described herein.

also provides these utilities. Thus, the engine constituting the pumpmotor can be used to provide electrical power withappropriate takeofis.The ice slurry capability can be used to provide drinking water by thefreezing method of desalination. Hot water can be provided as notedabove. Accordingly, a complete utility ered in connection with theaccompanying drawing in whichlike referenced numerals designate likeparts throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration ofa refrigeration system made in accordance with the present invention;and

FIG. 2 is a detailed view, partly in section, of the evaporator utilizedin the refrigeration system of FIG.

DETAILED DESCRIPTION Referring to FIG. 1, there is shown an exemplaryembodiment of the refrigeration system made in accordance withprinciples of the invention. The refrigeration system comprises a motor12 which normally may be air-cooled and can be conveniently mounted on adeck of a, small boat. The motor 12 can be a fossil, and fuel internalcombustion engine, such as spark ignition or diesel can be electricallyor hydraulically driven or driven by a belt driving mechanism. The motor12 is used to drive a shaft 14 having a pulley l6 thereon. The shaft 14in addition is connected through a clutch member 18 to a compressor 22and is used to drive the compressor 22. The compressor 22 comprises asuction input section 24 and discharge output section 26. The pulley 16has a belt 28 thereon which is used to drive a second pulley 32. Thepulley 32 is mounted on a shaft 34 which is used to drive a brine pump36 and also is connected through a coupling 38 to a coolant pump 42.Alternatively the brine and coolant pumps 36 and 42 can be tandemlydisposed on the same shaft and/or driven off the same belt as thecompressor. The refrigeration system is normally utilized to chillseawater or if desired, to recycle the chilled seawater, reducing thetemperature of the seawater sufficiently that a slurry is produced.

Seawater is positively drawn into the refrigeration system by means ofthe brine pump 36 through a strainer 44. Normally, the suction prime ofthe seawater to the pumps is maintained by a check valve 45 onceoperation is established in order to avoid dry sucking by the pumps. Thestrainer 44 prevents gross entrained solids in the seawater fromentering the system. The seawater is pumped through a tube 46 by thebrine pump 36 into the evaporator 48 of the refrigeration system. Thechilled seawater emerges from the evaporator 48 through a hose outlet 52where it can be used as desired. Thus, (not shown) the outlet 52 can beconnected, to a treating tank which, in turn, is connected through avalve to the inlet of the brine pump strainer. Other means ofdistributing the flow can be used such as high velocity spray, fog, andthe like.

Liquid refrigerant, which may be any conventional refrigerant such asany common halogenated hydrocarbon refrigerant, e.g., Freon, leaves acapillary expansion tube 64 and enters the evaporator 48 through a line54 where it boils at a low temperature to produce cooling and emergestherefrom into an output refrigerant line 56. The refrigerant is thenconveyed through a reversing valve 58 into a line 60 and then to anaccumulator vessel 62 as shownby the arrows. At the accumulator 62, heatfrom the liquid refrigerant flowing in the capillary tube 64 contactsthe accumulator 62 at a point upstream from the line 54, flows throughthe vessel wall and into the refrigerant vapor leaving the evaporator48. Such heat transfer causes the vaporization of any remainingrefrigerant liquid trapped in the accumulator providing protection tothe compressor 22 from liquid entrainment. The heat transfer alsoprovides a high degree of thermal efficiency by recovering unusedrefrigeration affect from the unevaporated refrigerant leaving theevaporator (recuperation).

The refrigerant vapor in the accumulator 62 is then conveyed by line 66to the suction end 24 of the compressor 22 where the pressure andtemperature of the gaseous refrigerant is raised. The refrigerant isdischargedfrom the discharge end 26 of the compressor to the reversingvalve 58 and then passes through a line 72 and then through a condenser74. To expediteremoval of heat fromthe refrigerant at the condenserstage, seawater is carried through a strainer 76 by means of the coolantpump 42 and passes from the coolant pump through a line 78 through thecondenser 74. The cooling water is emitted from the condenser through aline 80 and is then discharged overboard.

The strainer 76 and check valve 82 are similar to the strainer 44 andcheck valve 45 and functions with the coolant pump 42 in a manneridentical to that described with respect to the brine pump 36. Thefunctions of the brine pump and the coolant pump can be combined withappropriate valving so as to provide sufficient seawater for bothcooling the condenser and providing input seawater to the evaporator.

The output liquid refrigerant from the condenser is conveyed through astrainer-dryer 84 and is then conveyed through the capillary tube 64.The refrigerant in the capillary tube 64 is then conveyed to a secondstrainer-dryer 86 which provides the same function as the strainer-dryer84 during reverse operation as will be explainer hereinafter. The outputof the strainer-dryer 86 is then connected to the refrigerant line 54 atthe input of the evaporator 48. Thus, the refrigerant cycle is completedand the desired chilled seawater is produced at line 52.

Should it be desired to produce hot water at the output line 52, it ismerely necessary to reverse the connections of the valve 58 so as toreverse the flow of the referigerant through the system as shown by thedotted lines 88 and 90 in the valve 58. In the hot water mode ofoperation, refrigerant from the discharge end 26 of the compressor 22 isconducted through the line 88 and the line 56 and into the evaporator'48 whereupon the resultant heat exchange therein produces hot water atthe output of the line 52. The refrigerant passing through theevaporator in the line 56 exits through the line 54 where it enters thestrainer-dryer 86 which, as previously mentioned for reverse operation,will produce the same function as the strainer-dryer 84. The refrigerantthen passes through the capillary expansion tube 64, the strainer-dryer84, condenser 74, line 72, line 90 of valve 58, line 60, the suctionaccumulator 62 and then enters the suction end 24 of the compressor 22.Thus, the system can be used to produce hot water rather than chilledwater, when such is desired.

v the refrigerated chilled water at the output of the evaporator 48. Anice/brine slurry can be provided by recycling the chilled water at theoutput 52. This can be accomplished by reconveying the chilled seawaterthrough the brine pump 36 as shown by dashed line 92. This provides thecapability of adjusting the output temperature while preserving themonotube positive displacement character of the system. Thus, theresultant recycling can reduce the temperature of the slurry at theoutput of the hose 52 to 15F. Thus, the capability of continuouslyfreezing seawater is provided. Since the brine pump 36 is a positivedisplacement pump, any ice crystals formed in the single line 46 or inthe monotube section of the evaporator connected to the line 46 arepushed therethrough by the increasing pressure applied by the pump asthe seawater becomes more viscous or as the tube becomes restricted. Themonotube evaporator design coupled with the positive displacement brinepump creates an increasing shearing action at any spot where localbuild-up of ice scale would occur, thereby keeping the tubefree-flowing, the ice/- brine slurrywell mixed and the ice crystalsextremely fine in texture.

Referring now to FIG. 2, there is shown a preferred embodiment of theevaporator 48.utilized in the construction of the refrigeration systemof FIG. 1. The evaporator 48 comprises an inner coiled tube 102, one endof which is connected to the output line 52. Surrounding the coiled line102 in an outer coiled line 104,

one end of which is connected to the refrigerant line 54 and the otherend of which is connected to the refrigerant line 56. In a typicalconstruction, the line 102 is formed of a it; inch outer diameter tubeof about 50 feet in length, and the tube 104 surrounding the tube 102 isfonned with a 5 1 inch outer diameter. Such a coiled tube-within-a-tubeconstruction efficiently produces chilled seawater having a temperaturein the range of 29-39F, and an ice/slurry when recycled as above.

The condenser 74 may be constructed in a manner similar to theevaporator 48 wherein an inner tube containing the seawater issurrounded by an outer tube containing the refrigerant which is cooledand condensed as it passes in annular countercurrent flow arrangementwith the seawater in the inner tube. Coiling of the tubes as illustratedresults in an advantageous economy of space and portability. Theevaporator and condenser coils can be nested one within the other,permitting compact enclosure which facilitates sliding, skidding andother handling and installation of the unit. The enclosure can be madeas a Water-proof hull for flotation on the surf and between boats atsea.

Referring back to FIG. 1, there is illustrated, in shadow, a furtherembodiment wherein means are provided to chemically treat the brineapplied to the fish.

said pump upstream of 6 Specifically, a hold tank 55 is provided whichmay be in the form of a container, pressure vessel, flexible feed bag,drum or the like, and which is connected into the I brine pump strainer44 through a valve 59 as shown or ity system for converting seawaterinto refrigerated seawater, comprising:

single drive means; an evaporator for lowering the temperature ofseawater, said evaporator comprising an outer coiled evaporator tube andan inner coiled evaporator tube within and coextensive with said outerevaporator tube and having a discharge end extending therefrom; arefrigerant condenser comprising an outer coiled condenser tube and aninner coiled condenser tube within and coextensive with said outercondenser tube and having a discharge end extending therefrom;

refrigerant tube means for. connecting said outer evaporater andcondensure tubes constituting with said outer tubes a refrigerant line;

strainer means in said refrigerant line;

compressor means connected to said refrigerant line for circulatingrefrigerant therethrough and driven by said single drive means;

means for pumping seawater through said inner evaporator and condensertubes comprising at least one positive displacement-pump, and strainermeans therefor, connected to said inner evaporator and condenser tubesand driven by said single drive means, whereby to provide cooledseawater discharge from said inner evaporator tube discharge end andheated seawater discharge from said inner condenser tube discharge end;

valve means for reversing the flow of refrigerant through saidrefrigerant line whereby to produce hot water at the discharge encl ofsaid inner evaporator tube.

2. A system in accordance with claim 1 wherein said condenser andevaporator coils are nested.

3. A system in accordance with claim 1 and further comprising means forrecirculating said refrigerated seawater at the output of saidrefrigerator through said pump means to form the output of said innerevaporator tube as an ice/brine slurry.

4. A system in accordance with claim 1 and further comprising means forapplying fish treating agents to said evaporator.

1. A portable single drive, positive displacement utility system forconverting seawater into refrigerated seawater, comprising: single drivemeans; an evaporator for lowering the temperature of seawater, saidevaporator comprising an outer coiled evaporator tube and an innercoiled evaporator tube within and coextensive with said outer evaporatortube and having a discharge end extending therefrom; a refrigerantcondenser comprising an outer coiled condenser tube and an inner coiledcondenser tube within and coextensive with said outer condenser tube andhaving a discharge end extending therefrom; refrigerant tUbe means forconnecting said outer evaporater and condensure tubes constituting withsaid outer tubes a refrigerant line; strainer means in said refrigerantline; compressor means connected to said refrigerant line forcirculating refrigerant therethrough and driven by said single drivemeans; means for pumping seawater through said inner evaporator andcondenser tubes comprising at least one positive displacement pump, andstrainer means therefor, connected to said inner evaporator andcondenser tubes and driven by said single drive means, whereby toprovide cooled seawater discharge from said inner evaporator tubedischarge end and heated seawater discharge from said inner condensertube discharge end; valve means for reversing the flow of refrigerantthrough said refrigerant line whereby to produce hot water at thedischarge end of said inner evaporator tube.
 2. A system in accordancewith claim 1 wherein said condenser and evaporator coils are nested. 3.A system in accordance with claim 1 and further comprising means forrecirculating said refrigerated seawater at the output of saidrefrigerator through said pump means to form the output of said innerevaporator tube as an ice/brine slurry.
 4. A system in accordance withclaim 1 and further comprising means for applying fish treating agentsto said pump upstream of said evaporator.